Recently, services, such as SNS, that share content between particular users are increasing. Moreover, as a result of it now being possible to generate high picture quality content due to the increasingly high functionality of terminals, the size of shared content is ballooning, with a tendency for the waiting times for uploading and downloading content to get longer.
Methods that employ cache servers are widely utilized as methods to shorten the waiting times for uploading and downloading content. For example, for content accessed by many unspecified users under a cache server, frequently-accessed content is distributed to that cache server. This enables the time taken to download content to be shortened for users under that cache server.
There has also been a proposal, when transmitting data, to select, from plural cache servers, a cache server that has a light load and a short delay when communicating with a client, and to distribute data from that cache server to the client.